Saint Mael (also spelled Mel or Moel) was believed to be a Briton and the son of Conis and Darerca who was the sister of Saint Patrick. It is unknown for certain the year in which he was born. He came to Ireland with Saint Patrick and two of his brothers; Melchu and Muinisn (both of whom are also saints). Like many Celtic Priests of his era, St. Mael worked to support himself rather than earn a stipend as clergy. He was ordained in Ardagh and was appointed by Patrick to pastor the church at Ardagh which Patrick had built himself and founded in 454 AD. Mael was consecrated a Bishop but had no see himself, mostly evangelizing Ireland as prescribed by Patrick. It is believed that Mael shared the Episcopal see with his brother Melchu although most likely (since we know Mael didn't have a fixed see based on accounts from St. Brigid) Melchu was the Episcopal head of the Holy see at Armagh and Mael was the Abbot of the adjoining monastery at Ardagh. It was not uncommon for the rank of Abbot to be on a parallel tier as Bishop and it would have been unusual for Patrick to have established a co-episcopacy.

St. Mael was known for his generosity to the poor living himself only on what was essential and giving the rest of his earned income to the poor throughout county Longford. A firm believer in the monastic life, Mael was always eager to find candidates for religious life. One such candidate was Brigid of Kildare. It was Saint Mael that established her as a nun overseeing her vows. It is said that Mael "accidentally" consecrated St. Brigid a Bishop, although "accidentally" is said tongue in cheek as many believe he deliberately meant to consecrate her a Bishop. Even St. Patrick had admitted she was destined for great things and in fact, she established several monasteries throughout Ireland much like a Bishop or Abbot would have.

For a while, St. Mael lived with his Aunt Lupait to help her farm the land she lived on. During this time rumors developed that there might have been more going on between the two than just farming. St. Patrick came to investigate these allegations himself. As a result of the scandal, both Mael and Lupait prayed for vindication and each was able to perform a miracle. Lupait was able to carry hot coals without burning herself or her clothing, and St. Mael plowed the earth, and then retrieved live fish from the trough. After both were cleared of the charges Patrick suggested that Mael do his Fishing in the water and plowing on land. St. Mael returned to his Monastery at Ardagh where he died in 489 of Natural Causes.

St. Mael is the Patron Saint of the Diocese of Ardagh and Clonmacnois Ireland and his feast day is February 6th.